Firearm receiver



FIG. 1 is a right side elevational view of a firearm receiver, showing my new design;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a front elevational view thereof;

FIG. 5 is a left side elevational vew thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a front, top and right side perspective view thereof. 

The ornamental design for a firearm receiver, as shown. 